TPS61256C: wrong output with my PCB design

Cho Seonghun

Part Number: TPS61256C

Hi please refer to following PCB design

But the output is about 2.5V..

what is the problem??

Should I need to connect A1,A2 and B1,B2?

Thanks.

0 Zack Liu over 4 years ago

Hi Seonghun,

I can't see your layout. Can you share it again?

0 Cho Seonghun over 4 years ago in reply to Zack Liu

0 Zack Liu over 4 years ago in reply to Cho Seonghun

Hi Seonghun,

I don't understand. How did you connect the external components? You need to follow the datasheet layout guideline. Otherwise there will be problems.

0 Cho Seonghun over 4 years ago in reply to Zack Liu

Thanks for your reply

My question is that should I connect both A1,A2 which is Vin and both B1, B2 which is sw?

or can I just use one of them like my picture?(just use A1 and B1)

can you explain with the chip design why there are 2 pins for Vin(A1,A2) and SW(B1,B2)

Thanks

0 Zack Liu over 4 years ago in reply to Cho Seonghun

You have to connect both A1, A2 to Vin, B1, B2 to SW.

One pin cannot flow so much current.

It's not suggested to use bread board to test the IC.

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